Cupola-furnace



v (No Model.) 2 Sheets-Sheet 1.

J. J. JOHNSTON.

GUPOLA FURNAGB.

No. 312,727. Patented Peb.24,1885.

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(No Model.) 2 Sheets-Sheet 2.

J. J. JOHNSTON.

- GUPOLA PURNAGE. l N0. 312,727. Patented Feb. 24, 1885.

INVENTOR.

"Nunn STATES Arnnr JAMES J. JOHNSTON, OF COLUMBIANA, OHIO, ASSIGNOR OFSEVEN-EIGHTHS TO WILLIAM W. GIBBS, OF PHILADELPHIA, AND ALBERT C. ELLIS, OF

PITTSBURG, PENNSYLVANIA.

CUPOLA-FURNACE.

SPECIFICATION forming part of Letters Patent No. 312,727, dated February 24, 1885.

Application filed December 13, 1883. (No model.)

To LZ/ whom, t may concern:

Be it known that I, JAMES J. JOHNSTON, of Columbiana, in the county of Columbiana and State of Ohio, have invented a certain new and useful Improvement in Cupola or Melting Furnaces; and I do hereby declare that the following is a full, clear, and eXact description thereof, reference being had to the accompanying drawings, and to theletters of reference marked thereon.

To enable others skilled in the art with which my invention is most nearly connected to make and use it, I will proceed to describe its construction and operation.

In the accompanying drawings, which form part of this specification, Figure l is a side elevation of my improvement in cupola or melting furnaces. Fig. 2 is a vertical section of the same. Figs. 3 and 4L are detail views.

Referencebeing had to l[he accompanying drawings, A represents the cupola or melting furnace, which' is of ordinary construction, with the exception that it is provided with three 'or more teasingopenings,77 B, arranged around the circumference of the cupola in the same horizontal plane, and a chargingchamber, C, having a door, D, and a pipe, E, communicating with the bore of a stack, F, and provided with a damper or cap, G, and

the pipe E, provided with a steam-jet pipe, H, having a valve, I. The blast-pipe J, connected to the air-jacket K, is provided with a valve, L, for regulating the flow of air into the jacket K. The stack F is provided with a 5 door, M, having a fre-brick lining, N. Above the door in the bore O of the stack Fis arranged a coniform sparlcarrester, I, which is arranged concentric to the bore of the stack, leaving a narrow annular space around its 4o base, for. the escape of gases and waste heat, and is furnished with a tire-brick lining, Q. The stack F is provided with a pair of winding stairs, for ready and easy access to the doorM of the stack. The construction of the air-jacket K and the openings communicating between it and the bore of the cupola are clearly shownin Figs. 3 and 4. It is frequently the case that the cupola becomes cloggedthat is to say, the burden becomes arched by thelowerportionofthechargedroppingdown, 5o leaving a portion of the burden arched above it, and experience `has demonstrated 'that this clogging or arching is formed a short distance above the air-jacket, or at about the point where I have placed the teasing-openings B, which openings are used for the purpose of loosening up the clogged and arched portions of the burden, the advantage of which will be apparent to the skilled cupola-man. The charging-chamber C is of such construction and size that a charge of pig-iron may be placed in it and the door D closed. By this arrange ment of the charging-chamber the disadvantage attendant upon the charging of the cupola with cold pig-iron after it has received its burden may be entirely avoided. The stack F is provided at -its base with a door, V, for the purpose of access to the interior for the removal of cinders and other refuse that may accumulate therein. The steam Ajet being op- 7o posite to and on the same horizontal plane with the charging-chamber C, it will relieve the cupola-man from the intense heat during the operation of charging the coke and metal.

The foregoing description willcnahle the skillful mechanic to construct my improve ment in cupola or melting furnaces. I will therefore proceed to describe the operation. The pipe J being connected to any known air-pressure device, and the pipe H commu- 8o nicating with a steanrgenerator, and Athe cupola A prepared in the ordinary manner and charged with its burden, the operator places an additional charge of pig-iron in the chain ber C and closes the door D. The cap or 8 5 damper is'elevated andv held in that position by the damper-rod S being hooked on the catch T. The cap or damper is held up during the heating up of the cupola, and is closed down and kept closed before the blast 9o is put on. The valve I is then opened, thereby starting the steam-jet, which will draw off and force the deleterious gases and refuse of combustion into the stack,- and at the same time cause au intense heat in the cupola. After the steam-jet has been in operation for about five or ten minutes the valve L is opened, which will allow the desired flow and pressure of air to pass into the jacket K, and from it will be distributed by means of the openings U into and through the burden of coke, iron, and luxing material constituting said burden or charge By the combination ot' the steam and air blast under' pressure the melting power or capacity ofthe cupola is at least increased twofold, and the burning coke and melting and melted iron are kept free from the injurious effects of the deleterious gases evolved from said burning coke and the iron in process of melting. l

The advantage otA carrying off the sulphur,

phosphorus and deleterious gases evolved during the operation ot' melting and in advance ot' the air acting upon the burning coke and iron will be apparent to the metallurgist and skilled cupola-mau. The deleterious gases carried off and the oxygen ot the air under pressure acting upon the burning coke and the melting and downward-llowing iron comparatively free from said deleterious gases, the melting process will be greatly facilitated, the Iiuidity ofthe iron increased, and a stronger and purer metal produced.

By the combination of the stack F, coustrueted as hereinbel'ore described, with the cupola having a damper or cap, G, the danger incident to the constant flow of red-hot einders,

sparks, and tlame 'from the top ot' the cupola is entirely avoided, and the buildings adjacent to the foundry will be 'free Afrom nuisance occasioned by said einders, sparks, and the other refuse of combustion common to the ordinary cupola.

I am aware that it has been heretofore proposed to use a steam-j et in combination with a cupola-furnace for the purpose of entraining air through openings in the base of the latter, and in connection with other furnaces, for facilitating the discharge of the products of combustion.

I ani also aware that in connection with a blast under pressure at the base of other i'urnaees 'fans and like means have been einployed for carrying off such products. Steamjets have heretofore been located above the charging-opening and in proximity thereto; but the arrangement has been such that the hot gases were drawn past the opening and not to one side and away from it, as in my device.

Y I ain also aware that an auxiliary stack has been heretofore used for receiving the products ofcombustion, and do not claim, broadly, such construction. V

Having thus described my improvement, what I claim as ot' my invention isl. In a cupola or melting furnace, the conibination, with the stack, ot'au exit-flue leading therefrom and provided with a central steamjet pipe and a charging-chamber, the steamjet pipe and charging-chamber being arranged opposite each other in the same horizontal plane, whereby outtlow of heat and gaseous products during the charging operation is obviated. substantially as shown and described. 2.- lhe combination ot' the cupola A, having a cliaiging-chamber, C, cap or damper G, pipe E, steam-jet pipe II, and stack F, having spark-arrester I), substantially as herein described, and tor'tlie purpose set forth.

JAMES J. JOHNSTON. llfitnesses:

E. Joi-msToN, lVM. E. Dran. 

